58 ANTISEPTICS AND DISINFECTANTS. 



tremely variable in strength and the results of their use 

 uncertain. They all deteriorate very rapidly. Peroxide is 

 used principally for cleansing suppurating wounds, as it pos- 

 sesses the power of liberating nascent oxygen, which oxidizes 

 the purulent secretions. 



lodoform is very mildly antiseptic and possesses slight- 

 germicidal power. Its odor was for a long time accepted as 

 an evidence of its antiseptic power. Its action is due entirely 

 to the liberation of its iodine. 



Carbolic acid : This is the best known and most widely 

 used disinfectant. It is used in strengths of from 1 to 5 per 

 cent. Like mercury, it forms insoluble albumin compounds 

 which interfere with its penetrating power. By combining 

 carbolic acid with an equal amount of hydrochloric acid its 

 germicidal power is increased considerably. Anthrax spores 

 are destroyed in three hours if exposed to a 5 per cent, solu- 

 tion at the body temperature. The tubercle bacillus is killed 

 in thirty seconds. Creolin, lysol, trikresol, and similar prepa- 

 rations, possess the same germicidal power as carbolic acid. 



Sulphur is used very extensively for the disinfection of 

 sick-rooms after contagious diseases. It is used commonly in 

 the form of a sulphur candle, which is placed on a tin pan, 

 floated in a basin of water, and lighted. The room should be 

 closed tightly, so as to confine all the vapor. When pow- 

 dered sulphur is used, it is placed on a bed of sand or ashes 

 in an iron pot surrounded by water before ignition. The 

 action of the fumes is much greater if the air in the room 

 contains an excess of moisture. This is obtained by evapo- 

 rating a gallon of water in the room just before igniting the 

 sulphur. Liquid sulphur dioxide may be used. It vaporizes 

 at the room temperature. 



The antiseptic and germicidal value of sulphur has been 

 much overestimated, and it is not used so extensively as it 

 was some years ago, it having been displaced by a much more 

 active agent, viz. : 



Formaldehyde : One of the most active disinfectants and 

 germicides is formaldehyde. It is obtained in the market 

 under the trade name of formalin or formalose, a 40 per cent, 

 aqueous solution of the gas formaldehyde. The gas is ex- 



